Vaccines effective against SARS-COV-2 ‘MU’ Variant

The National Institute for Communicable Diseases (NICD) said its confident that vaccines currently being rolled out in South Africa will have high levels of protection against newly identified Covid variant “Mu”.

The World Health Organisation has recently classified the PANGO lineage B.1.621 (nextclade assignment: 21H) as a “variant of interest” (VOI) and assigned it the Greek name “Mu”.

This variant was first detected in Colombia in January 2021 (Laiton-Donato, 2021, medRxiV). 

ALSO READ: Mu B.1.621: Now classified as Covid-19 variant of interest

It has since spread across North America, South America and Europe, with detections in Asia.

The majority of the Mu sequences (5123) have been detected in North America (55%, n=2841) followed by South America (23%, n=1328), Europe (18%, n=948) and Asia (0.1%, n=6).

To date (3 September 2021) there have been no cases of Mu detected on the African continent, including South Africa.

Currently it accounts for less than 1% of the globally circulating viruses with delta accounting for 88%. 

“In addition to vaccination, we know that non-pharmaceutical interventions such as the wearing of masks, sanitising and washing your hands, keeping a safe distance and avoiding crowds are effective at preventing the spread of SARS-CoV-2 regardless of the variant,” said NICD in a statement.

The Network for Genomic Surveillance in South Africa (NGS-SA), which includes the NICD, continuously and rigorously monitors SARS-CoV-2 sequences circulating in South Africa.

This work is crucial in the early detection of SARS-CoV-2 variants, including Mu. 

The Mu variant is defined by the following mutations within the spike protein: T95I, Y144S, Y145N, 146N insertion, R346K, E484K, N501Y, D614G, P681H and D950N.

ALSO READ: New Covid-19 ‘variant of interest’ in SA mutates 1.7 times faster

Many of these mutations (T95I, E484K, N501Y, D614G, P681H and D950) have been seen before in other “variants of interest” or variants of concern, including beta and delta.

Some of these mutations have previously been associated with decreased antibody responses and increased transmissibility.

This variant will likely therefore have similar properties to other variants with increased transmissibility and reduced sensitivity to antibodies in vaccines and those who have recovered from Covid.